Tag Archives: June

The month began cool, but became warm in the second half. The only unusual daily temperature was the early morning reading of 12.0° on the 29th, 10.0° above normal. There were ten frosts, when there are normally thirteen. On several mornings there was fog in the valley.
Seven days (normally six) registered rain over 0.2 mm. Significant falls came around the 12th and the 29th. On the 29th, the reading was 23.4 mm, but the rain extended over more than one day, totalling 39 mm. It was neither steady nor heavy, but unusually persistent. At Tamworth, rain fell in 27 hours out of 30.

Comparing June months

June of 2016 had been the wettest and most cloudy of the new century, with warm nights and cold days to match. This June, while moist, was close to normal. It was very like June 2015 and June 2014.
The month’s total rainfall of 62.8 mm was at the 75th percentile, well above the June average of 44 mm. There are no shortages of rainfall for groups of months to this date.

Data. A Bureau of Meteorology automatic rain gauge operates in the museum yard. From 17 March 2017, 9 am daily readings are published as Manilla Museum, Station 55312. These reports use that rainfall data when it is available. Since that gauge records “0.2 mm” on many rainless days, I cannot call those days rain days if the monthly count of rain days is not to show a sudden jump to record-breaking numbers.

All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

June raw anomaly data (orange)

In June 2017 the daily maximum temperature was normal. Moisture variables were low on the graphs, showing rather high moisture. Both daily minimum temperature and subsoil temperature were high. For each variable, the raw value was close to the smoothed value of June 2016, just twelve months earlier.

Fully smoothed data (red)

The latest available fully-smoothed data point, December 2016, showed warming and drying. Only the dew point anomaly had just passed a “dry” peak. Smoothed subsoil temperature anomaly, which had reached a record low value in November, began to rise, like both of the air temperature anomalies.

The Mackellar cycle

Manilla’s climate variables often move in the cycle of “droughts and flooding rains” from Dorothea Mackellar’s poem “My Country”.*

In that cycle, temperature and moisture move together: hot with dry, cold with wet. On my graphs, hot is to the right. The top four graphs have dry at the top. (I count daily temperature range anomaly as a moisture indicator: high values show dryness.)

The “Mackellar cycle” drives the anomaly values up and down the blue trend lines that skew from cold-and-wet at the lower left to hot-and-dry at the upper right. The path is seldom straight, as any lead or lag of moisture will curve it into an ellipse.

Ellipses on the graphs show the cycle has been strong for two years since the winter of 2015. Its period has been very short: only twelve or thirteen months. Daily maximum air temperature anomaly reached a peak in February of both 2016 and 2017 (hot in late summer-autumn), and reached a trough in August-September 2016 (cold in late winter-spring).

On the top four graphs the cycle advances around an ellipse clockwise. A peak of dryness (up) comes several months before the related peak of daily maximum temperature anomaly (right). Similarly, wetness (down) comes before low temperature (left). I have posted already about the way this cycle skewed the seasons in 2016.

The two graphs at the bottom contain only temperatures. Circles on those graphs show that both the daily minimum temperature anomaly and the subsoil temperature anomaly have been lagging the daily maximum temperature anomaly by several months during these last two years (and not before).

In a post to a “weatherzone” forum, I have annotated (in green) the graph for Dew Point Anomaly versus Daily Max Temp Anomaly. It is the one that shows most clearly the elliptical trace caused by the cycles. That forum thread: “Climate Driver Discussion 2017 (Enso, IOD, PDO, SAM etc.)” has almost no reports of climate cycles observed in Australia.

Note:

Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

* Normal values for rainfall are based on averages for the 125 years beginning 1883.

This was the fifth wettest June in history, and had the second coldest day in this century.
Average temperatures were several degrees high until the last week, when they fell to three degrees low. In times of cloud and rain, cold days followed warm nights; at other times warm sunny days followed cold nights. There was one extremely warm night and one extremely cold day. The night before the 19th did not get cooler than 12.8°, making it the 5th warmest June night in this century. On the 27th the maximum temperature was only 8.5°: the second coldest day in this record from 1999. People remember the Friday before Queen’s Birthday in 2007 being bitterly cold, but that day reached 8.8°. The 20th of that month was the coldest, reaching only 8.3°.
This month, there were 8 frosts (usually 13) the coldest night being -1.8° in the screen.
Rain fell on 17 days, one day short of the record number here in any month (18 in June 1950!). The highest reading was 37.0 mm recorded on the 5th. As in May, the afternoon humidity was very high (seldom below 50%).

Comparing June months

The mean daily maximum temperature (16.4°) was very low, just not nearly as low as in June 2007 (14.3°). On the other hand, the mean daily minimum temperature (5.8°) was very high, as it was in June 2005, 2008, 2009, and 2013. The average temperature for the month (11.1°) was 0.8° above normal. Similarly, the subsoil temperature (16.8°) was 1.5° above normal.
The daily temperature range, normally 15.0°, was 10.6°, the narrowest yet seen in June, narrower than in 2007. Skies were rather cloudy, and the dew point normal.
The phenomenal rainfall of 114.8 mm was in the 97th percentile. There have been four wetter June months since 1883, but they were all before 1931. Thus, this is the wettest June in 86 years! Now, the greatest rainfall “shortage” is the 36-month total (1636 mm) which is in the 16th percentile. Greenhatch Creek is barely flowing, and a neighbour’s dam is almost full.

Data. Rainfall figures for this month are from the automatic rain gauge at Manilla, published on the internet by the Bureau of Meteorology as Station 55031. All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

June raw anomaly data (orange)

In June 2016, raw anomalies for all moisture variables became very high, while daily maximum temperature became very cool. Rainfall was more than 70 mm higher than normal (40 mm), and daily temperature range more than 4 degrees narrower than normal (15 degrees). Skies were cloudy and the dew point high. The two other temperature variables did not conform. Daily minimum temperature anomaly was very high, making the climate more coastal. Subsoil temperature anomaly was also high: the curve shows it trailing daily maximum temperature anomaly, after leading it for years.

Fully smoothed data (red)

Fully-smoothed data are now available up to December 2015. In general, it was a time of normal climate. Anomalies were small and changing only slowly. Daily maximum temperature was rather high, and dew point rather low.

Note:

Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

* Normal values for rainfall are based on averages for the 125 years beginning 1883.

The first week of June was cold but sunny, the second warm, and the rest not quite so warm. Rain registered (unofficially) on the 17th was 54.5 mm. That was close to the record June day of rainfall at Manilla Post Office: 55.1 mm on 18/6/1930.
The early morning minimum of the 17th was extremely warm, at 12.8°: the fifth warmest for June. There were 12 frosts (as usual) but none was severe. On two mornings, fog persisted past nine o-clock.

Comparing June months

Most monthly averages were near normal. Daily minima were up one degree, and morning dew points down one degree.
While lower than in June 2013, the total rainfall of 74.4 mm is high: in the 82nd percentile. Among rainfall totals for more than one month, there are no serious shortages. The lowest percentile value (11th) is for the 24-month total of 996 mm.

Data. All data, including subsoil at 750 mm, are from 3 Monash Street, Manilla. Rainfall data up to 26/3/15 is from Manilla Post Office, Station 055031.

Parametric plots of smoothed climate variables at Manilla
“June 2015: back to normal”

June raw anomaly data (orange)

Nearly all raw anomalies for the latest month are nearer to normal than the partially-smoothed anomalies of the autumn months. They are also quite close to the smoothed values of a year ago. Rainfall stands alone as a high value.

Fully smoothed data (red)

In December 2014, most anomalies were normal, or near normal, and changing only slowly.

Note:

Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

* Normal values for rainfall are based on averages for the 125 years beginning 1883.

This post is the fourth in a set for the 12 calendar months. Graphs are sixteen-year logs of the monthly mean anomaly values of nine climate variables for Manilla, NSW, with fitted trend lines. I have explained the method in notes at the foot of the page.

Trend lines for June

Heat Indicators

The trend of mean temperature rose from zero at first to stay at 0.5 deg from 2004 to 2010, then rose again.
The trends of daily maximum and daily minimum temperature anomalies were mirror-reversed about the mean trend line. The maximum line reached a peak in 2003 and a trough in 2009, while the minimum line did the reverse. The subsoil temperature anomaly trend was slightly low in 2004 and was high in 2014.

Recent Posts

Back-dated monthly reports

Monthly and seasonal weather reports for Manilla now extend back more than nine years to June 2007. [Select ARCHIVES for the month following.]
"Manilla 3-year climate trends" graphs and reports extend back to May 2010 as consecutive months. Earlier graphs and reports are accessed in ARCHIVES September 2002, 2004, 2006, and 2008.